The present invention relates to the industrial coupling industry and, more particularly, to industrial couplings and related methods particularly for industrial system industries.
In an industrial system such as a power generation system, for example, a rotor is conventionally positioned within a stator to generate power through magnetic induction as the rotor rotates within the stator. The rotor has a plurality of coils positioned in slots formed in the outer surface of the body of the rotor and also has coil end-windings which also extend along the proximal and distal end peripheries of the rotor body. These end-windings are often protected by a retaining ring that is positioned over the rotor shaft and substantially surrounds and retains the end windings within a predefined area. Additionally, an end plate is often placed over the end windings to protect the end windings in the axial direction, and likewise, the retaining ring protects the end windings in the rotational direction.
In such a power generation system, for example, between the generator rotor and a turbine, the shaft 71 from the rotor 72 and the shaft for the turbine often couple together. In order to get a retaining ring 75 or end plates over the coupling 70 of the rotor shaft 71, the retaining ring 75 has to have an outside diameter larger than the rotor shaft coupling 70. If this is not the case, the coupling 70 cannot be integral with the shaft. For strength purposes, the coupling 70 is preferably formed integral with the rotor shaft 71 as shown in Prior Art FIG. 2. As an alternative, and as shown in Prior Art FIG. 3, the coupling 80 for the rotor 82 is often placed on the rotor shaft 81 after the retaining ring 85 is mounted into position over the rotor shaft 81 and over the end windings 87. The coupling 80 can then be heat shrunk onto the shaft 81 by techniques well understood by those skilled in the art and such as shown in U.S. Pat. No. 4,671,696 by Suzuki et al. titled xe2x80x9cShaft Assembly And Manufacturing Process Thereof,xe2x80x9d U.S. Pat. No. 4,567,649 by Ades et al. titled xe2x80x9cSystem For Heating, Disassembly, Handling And Reassembly Of A Turbine Rotor,xe2x80x9d and U.S. Pat. No. 6,234,729 by Cook titled xe2x80x9cShrink Fit Shoulder Interface.xe2x80x9d To keep the coupling 80 and shaft 81 alignment from shifting, however, separate shaft keys 88 are often used to enhance the strength, position, and alignment of the coupling 80 with the rotor shaft 81. A problem with a shrunk-on type coupling 70 (FIG. 2) requiring keys 88 is that it is much more labor intensive, requires more parts, and also reduces the strength of the coupling connection with the shaft 81. Accordingly, there is a need for a coupling that does not require keys and enhances the overall strength of the connection.
With the foregoing in mind, the present invention advantageously provides a power generation system or other industrial system having an industrial coupling, and associated methods, which advantageously strengthens the connection between an industrial coupling and a shaft. The present invention also provides a power generation system having an industrial coupling which advantageously is easier to mount and assemble and has fewer parts to couple the rotor shaft to the turbine shaft in a power generation system or other industrial couplings. The industrial coupling of the present invention is also advantageously less expensive and easier to manufacture because it has fewer parts and is particularly advantageous for situations where the diameter of the coupling up to the through bolt openings is less than the inside diameter of the opening formed in the retaining ring, end plate or other industrial member which needs to be positioned over the rotor shaft and the coupling. Advantageously, to accomplish this, the present invention allows the strength of the coupling to be transferred directly to the shaft in a manner that enhances the overall strength of the coupling without the use of keys. Because the through bolts advantageously in effect act as the keys for alignment purposes, the strength of the overall coupling is enhanced by directly transferring strength from the coupling to the shaft without the use of separate shaft keys.
More particularly, an industrial system according to the present invention preferably includes a drive such as motor, engine, or a turbine of a power generation system and a driven component such as a compressor or generator of a power generation system. Although the invention is applicable to various types of industrial systems, it is particularly advantageous for a power generation system and is described for clarity purposes herein in this context. A power generation system, for example, preferably includes a power generator having a generator rotor with a first rotor shaft and a turbine positioned to drive the generator and having a second turbine shaft. A first industrial coupling preferably is connected to the first shaft to couple the first shaft to the second shaft. The first coupling preferably has a first coupler portion mounted to and integrally formed with the first shaft. The first coupler portion preferably includes a first bore hole portion having a first plurality of notches formed therein, and a second coupler portion mounted on the first coupler portion and including a second bore hole portion having a second plurality of notches formed therein so that the combination of the first plurality of notches in the first bore portion and the second plurality of notches in the second bore portion define a first plurality of bore holes of the coupling. A second coupling preferably is connected to the second shaft and positioned adjacent the first coupling. The second coupling preferably has a second plurality of bore holes extending therethrough. Each of the second plurality of bore holes is preferably coaxially aligned with one of the first plurality of bore holes. A plurality of elongate through-bolts preferably is positioned through the first and second plurality of bore holes of the respective first and second couplings to connect the first coupling to the second coupling and thereby couple the first shaft to the second shaft.
The present invention also advantageously provides an industrial coupling preferably adapted to be positioned to connect a first shaft of a portion of an industrial system to a second shaft of a portion of an industrial system so that an industrial member having an opening formed therein and having a preselected opening diameter can be readily positioned over the coupling. The coupling preferably has a first coupler portion mounted to and integrally formed with the first shaft and having a first diameter less than the preselected opening diameter of the industrial member so that the industrial member can readily be positioned over the first coupler portion and onto the first shaft. The first coupler portion preferably includes a first bore hole portion having a first plurality of notches formed therein. The industrial coupling preferably also has a second coupler portion adapted to be mounted on, e.g., and more preferably heat shrunk on, the first coupler portion and having a second diameter greater than the preselected opening diameter of the industrial member when mounted on the first coupler portion so that the industrial member after being positioned onto the first shaft cannot be readily positioned over the coupling. The second coupler portion preferably includes a second bore hole portion having a second plurality of notches formed therein so that when the second coupler portion is mounted on the first coupler portion the combination of the first plurality of notches in the first bore portion and the second plurality of notches in the second bore portion define a plurality of bore holes of the coupling.
The present invention further advantageously provides a method of mounting an industrial member having an opening with a preselected opening diameter formed therein over a shaft. The method preferably includes positioning the industrial member over a first coupler portion of a coupling mounted to the first shaft. The first coupler portion preferably has a first diameter less than the preselected opening diameter of the industrial member so that the industrial member is readily positioned over the first coupler portion and onto the first shaft. The first coupler portion preferably has a first bore hole portion with a first plurality of notches formed therein. The method of mounting also preferably includes positioning a second coupler portion on the first coupler portion. The second coupler portion preferably has a second diameter greater than the preselected opening diameter of the industrial member when mounted on the first coupler portion so that the industrial member after being positioned onto the first shaft cannot be readily positioned over the coupling. The second coupler portion preferably includes a second bore hole portion with a second plurality of notches formed therein so that when the second coupler portion is mounted on the first coupler portion the combination of the first plurality of notches in the first bore portion and the second plurality of notches in the second bore portion define a plurality of bore holes of the coupling.